Doordie,
Are those really Kawasaki option head gaskets? Cool! What ranges do they come in? I am very interested for my rebuild this winter. The squish clearance makes such a noticable difference in how the bike runs. I am always amazed a how many bikes come with waay too large of a squish clearance. In my view, the squish should be as low as reasonable with the compression ratio set by the head volume, but they never seem to get built that way. Often the squish is quite large and, as Doordie says, fuel/air is wasted on each stroke. Ideally the squish should be nearly zero, but since the rod grows with heat and rpm it has to have some clearance, around .025" for small up to .045 for large engines (feel free to correct me if I'm way off on the numbers - going from memory (old Jennings book memory)). For example my sons PW50 had .080" when it ought to be about .025". After milling I ended up with about .030" but the bike run overall much better. I once had a 2-stroke twin 350cc road race bike that had .200". Yuk! Following a tuning recipe from the UK, I tossed the head gasket and milled .100" off the head, putting the quish at around .030". What a big difference it made! Doordie, what squish clearance do you recommend for the KX and what do you normally find set them at from the factory. Thanks. Cam.